The weathering on the base was done using Scorched Brown basecoat, Rust Pigments. Sealed. Covered in Tim Holtz Distress Crackle paint - Old Paper leaving bits of the base showing through. Washed it with Nuln Oil and some Windsor and Newton Orange as looked right. Then I look a modelling knife and chipped further bits off. Then added more weathering pigments until it looked right.

Not used the GW on but other than the colour its probably pretty much the same stuff.